The sale of pornographic materials has long been one of the most contentious issues surrounding the right to free speech—and the rapid spread of online pornography has intensified this debate. Critics argue that online pornography makes indecent material more pervasive and easily accessible than ever before. They emphasize how easy it is for children to access such material.

The courts have traditionally upheld adults’ rights to view pornography, while also allowing laws that protect children from it. Free speech advocates, however, maintain that it is very difficult to use this type of regulatory framework on the Internet. Due to the nature of the medium, any attempt to limit children’s access to objectionable material will unavoidably limit adults’ access to it as well, undermining free expression on the web.

The federal government’s...